Drill head



May 6, 1952 Filed DGO. lO, 1945 J. MOON DRILL HEAD 2 SHEETS-SHEET lHYDRAULIC JACK HYDRAULIC JACK INA/EN Tok,

(IH/115,5 Moo AT TOR/Vex May 6, 1952 J. MOON 2,595,401

DRILL HEAD Filed Dec. 1o, 1945 2 SHEETS-SHEET 2 INVENTQR.

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Patented May 6, 1952 DRILL HEAD James Moon, Altadena, Calif.,.assignorto Signal Oil and Gas Company, Los Angeles, Calif., a

corporation of Delaware Application December 10, 1945, Serial No.633,934

Claims. (01;'255-23) n" invention relates toa combined drill head andmotor assembly.

In conventional rotary assemblies for rotary `drilling of bore holes foroil or gas wells, the drill pipe is rotated by and passed verticallythrough the rotary drill table. The drill pipe and casing is handled bythe conventional drilling rig. A conventional swivel is employed forpassage of mud fluid into the drill pipe.

It is an object of my invention to design a power operated drill headand swivel structure which may be mounted upon a power operated hoistand which will move together with the drill pipe as the drill pipeadvances during drilling and will also function to rotate the drillpipe.

My drill head is particularly adapted for use with hydraulicallyoperated jacks which are so mounted as to advance the drill pipe orcasing into or-withdraw drill pipe or casing from the bore hole.v

It is a further object of my invention to design such a drill headwherein the motive power for rotation of the drill pipe may be mountedwith the drill head and advance therewith, and to reduce the size of thepower unit by employing a plurality of such power units.

'It is an additional object of my invention to provide means fortransmitting the power to the drill head through a plurality of shafts,each separately connected to a source of motive power mounted inassociation with said drill head.

It is a further object of my invention to so mount the drill stem inassociation with the drill head that the loads imposed longitudinally ofthe drill stem are not transmitted to the gear system by which therotary power is transmitted from the shafts to the drill stem.

These and other objects of my invention will be better understood byreference to the accompanying drawings which illustrate a preferredembcdiment of my invention, and in which:

Fig. 1 shows an assembly view showing the mounting of my drill head on awell bore drilling machine;

Fig. 2 is an end View of Fig. 1; and

Fig. 3 is a sectional view of my drill head taken along the line 3-3 ofFig. 2.

In Fig. 1 the drilling machine I includes braces 2 which also act as thelongitudinal braces of the machine and the longitudinal braces 3.Transverse end braces 4 and transverse braces 5 and 6, and angularbraces l are also provided at .suitable places to impart rigidity to thestructure. y Mounted on transverse brace 6 is a pair of hydraulic jacks8 and 9. The cylindersv are mounted on 5 and pass through thetransvers'brace 5. The jack piston rods il' and Iii are connected to theyoke II which is mounted on rollers l2 adapted to roll on braces 2 whichact as tracks.

Mounted on cross brace 5 and connected to brace 3 is a pair of hydraulicjacks I3 and It. The jack piston rods are connected to yoke I5 whichmoves on rollers I8 guided on the braces 3' which act as trackstherefor.

Slips Il are mounted on brace 5 and slips Ii! on brace 6. Mounted onyoke I5 are the compound slips IS and 2). Bolted to yoke II is thecombination drill head and swivel assembly 2l.

The drill head box 22 (see Fig. 3) carries the cylindrical journal boxes23 in which are positioned the sleeves 2d carrying bearings 26 and 28.The .bevel gear 23' is mounted on hollow shaft 2l in bearing 26. Shaft2l is keyed in the tube 25 and mounted in bearing 2S and packed off at28a. The shaft 3l is driven by a gear formed of a ring gear 2S! mountedon a disc 3@ which rotates on ball bearings 3io. The hollow shaft 3I isdriven by 30 through the splines 3 Ia in bearings 3Ib and is packed olfat 33. The housing is bolted to I I so that the drive shaft 3l is inaxial alignment with the slips l'I and the drill pipe 4i. The shaft 3icarries a load disc 32 abutting against 3B. There is no rotationalconnection between 32 and 43E) except through shaft 3l via splines 3Ia.The shaft 3l operates against a thrust bearing 34 mounted in the housingcover` 35. Telescoping into shaft 3| and suitably packed by packing 36is a stationary tube 3l carried on the spider 38 formed integrally withthe cover 35. A ilange connection 39 holds the tube 3i in the spider andin the packing.

Mounted on the yoke I I' (see Fig. l) is a pair of power units 46connected to the shafts 2'I. These vpower units may be a pair ofelectric motors, such as synchronous motors connected to a common supplyof alternating current, or a pair of hydraulic motors connected inparallel to a common supply of fluid such as oil under pressure. Suchhydraulic motors are Well known and one example thereof is the typedescribed in Patents No. 2,320,727 and No. 2,313,407. These motors havethe characteristic such that for a given setting of the motor the speedis dependent on the volume of the applied uid and so long as this volumeis maintained constant for any motor setting, the speed of the motorremains constant. A

Fig. 1 shows two such Vickers hydraulic motors mounted on the yoke I Iand connected, one each, to the shafts 2l.

The use of such means of motive power with a plurality of gears 28 todrive the single gear 29, preferably spaced around said drive gear 29and in mesh therewith, and each driven by a separate power shaft 21, hasa number of advantages. It permits of the application of a large amountof power to the gear 29 while employing relatively small gears such as28', and thus the size of the gear box may be kept small. This is highlydesirable for a drill head which is to be mounted on the yoke II. Byplacing a number of gears 28' and the associated power unit at variouspositions around the periphery of the gear 21, the size of each powerunit can be minimized. Two such gears and power units are vshown in Fig.3. A larger number may be used. By using a multiplicity of small gearsinstead of a single gear, I am able to balance wear load on the gears28' and the gears 29 so as to get uniform tooth wear. By using amultiplicity of gears we are able to apply a total drive load to gear 28equal to the sum of the loads applied via each pinion gear. The totaltooth pressure is held to the pressure applied by the pinions and willthus be materially less than the tooth pressure required to transmit thesame load through one pinion gear.

Since, however, each gear 28' is operated from a separate power unit, Ihave found it desirable that the speed of all of the gears 29' be thesame. Where all the gears 28 are the same size, this means that theshafts 21 should rotate at the same R. P. M.

Where these shafts are operated from different power units there is adanger that these speeds cannot be kept at the desired equal R. EP. M. Ihave provided a simple means for obtaining this synchronized speed.Thus, by employing hydraulic motors such as described above andassuring, by proper manifolding, that the fluid pressure applied to eachmotor is the same and that the volume of fluid at such pressure is thesame to each motor, I can be sure that the motors will rotate all shafts21 at the same speed. This is accomplished by a balanced manifolding ofthe fluid inlets and outlets from the hydraulic motors and by adjustingthe setting of the hydraulic motors. As an alternative I may employ,when space considerations permit, A. C. synchronous motors in paralleldriven from the same source of A. C., so that each motor will turn atthe same speed determined by the current characteristics in the feedline. In these manners, also, I may rotate all shafts 21 at the samespeed.

The connection between shaft 3| and 39 forms a floating mounting ofdrive shaft 3|. As shown in Fig. 3, any upward thrust of the spindle 3|,occasioned as will be described below, will be transmitted to the thrustbearing 34 and will not be transmitted to the ring gear 29. This iscaused by the spline connection 3Iaand the absence of any connectionbetween 3l' and 3G whereby any thrust toward bearing 34 is transferredto the disc 30. This is important since it assures that the alignment ofthe gears 23 and 29 will be unaltered notwithstanding the sudden andlarge variations in load which occur during drilling, as will bedescribed below. Any upward thrust on the gear 29 will cause a jammingof the teeth of 29 into the teeth of 28 and thus cause an accelerationof wear and an excessive loading of gear 28.

Any reverse load on spindle 3l causes a pressure of the load disc 32against the disc Sil which is transmitted to the bearings 3Ic.Additionally, any thrust load occurring during rotation of 29 by 28 isalso taken up by 3Ic. In this manner 4 the relationship of the gears 29and 28 remains unaltered notwithstanding any sudden and large variationof load on the spindle 3 I In operation, the yoke II, being at itsextreme position with piston rods 9 and I0 in full retard position andits extreme position near 5the slips i1 are set to grip pipe 4I and theconnection at e2 is broken. The rods 9 and I9 are extended to separateII from 5 and a section of pipe is lntroduced and connected to the drillpipe in slips Il' and to connection 42. Slips I1 are opened and againthe pipe is advanced through the open slips Il by attaching the pistonrods 9 and I0. Zin this manner pipe is advanced until the drill d indrilling position in the bore hole. Slips il' are opened and 39 isconnected to a hose for mud iluid. The power is connected to '40 anddrilling is commenced. The gears 2S' rotate 29 and this rotates thespindle SI via the splines 3 Ia. The tube 31 is stationary While 3|rotates. As drilling is continued the mud is circulated down and throughthe swivel connection 31 through Si and down the drill pipe, and returnsup the bore hole outside the drill pipe.

In advancing the drill pipe by retracting the jacii piston rods 9 andIIJ, during rotation of the pipe by means of 3| or with the rotationinterrupted, the resistance to the advance of the drill pipe down thehole causes a thrust up the drill pipe and spindle 3i which is taken upby the thrust bearing 34 with the results described above.

When it is desired to withdraw the drill pipe from the bore, forexample, when the drill is to be changed, the reverse procedure isfollowed. With the slips I1 open the piston rods 9' and I0 are extended.The slips I1 are set to grip pipe di and the joint 'I2 is broken and thepipe uncoupled above the slips I1. The loosened joint is removed. Therods 9 and I9 are retracted and the pipe in the slips I'I is joined tothe spindle 3| by the joint 42. The slips I1 are freed and another jointof pipe 4I is withdrawn by extending the rods S and IIB. In this mannerthe pipe may be withdrawn from the bore.

In thus operating, the resistance of the pipe, due to its weight anddrag, causes a pull on the spindle 3| which is taken up in the bearings3I with the results described above.

Provision is made in the drilling machine for introducing casing. Withthe drill pipe entirely withdrawn from the well, casing is run throughthe slips I9, 29, and I8, and with slips I9 set and 2i) and I8 open, thecasing is introduced into the well by jacks I3 and Ill. In similarmanner the casing may be withdrawn by opening slips I9 and I8 andsetting slip 29.

While I have described a particular embodiment of my invention for thepurpose of illustra- "5 tion, it should be understood that variousmodifications and adaptations thereof may be made within the spirit ofthe invention as set forth in the appended claims.

I claim:

l. A bore hole drilling head, comprising a hollow drill pipe driveshaft, means for connecting said drive shaft to drill pipe, a drivegear, a spline connection between said shaft and said drive gear, saidshaft being driven by said gear through said spline connection, piniongear in meshing engagement with said drive gear, a power shaft for saidpinion gear, means for transferring the axial load on said drive shaftto said gear in one axial direction only, said means including a loaddisc on said drive shaft abutting the side of said drive gear betweensaid gear and said thrust bearing, the shaft being mounted forrelatively free movement in said gear in the opposite axial direction,and a thrust bearing for said gear mounted against the opposite side ofsaid drive gear.

2. A bore hole drilling head, comprising a hollow drill pipe driveshaft, means for rigidly connecting said drive shaft to said drill pipe,a drive gear, a spline Aconnection between said shaft and said drivegear, said shaft being driven by said gear through said splineconnection, a plurality of pinion gears peripherally spaced around saiddrive gear and each in meshing relation with said drive gear, a driveshaft for each pinion gear, a thrust bearing for said drill pipe driveshaft, means for transferring the axial load on said drive shaft to saidgear in one axial direction only, said means including a load disc onsaid shaft abutting the side of said drive gear between said gear andsaid thrust bearing, the shaft being mounted for relatively freemovement in said gear in the opposite axial direction, and a thrustbearing for said gear mounted against the opposite side of said drivegear.

3. A drill head adapted for rotating and advancing and lowering of drillpipe into and from bore holes for wells drilled in the earth, whichcoinprisesa housing, a hollow drive shaft in said housing, means forrigidly connecting said drive shaft to said drill pipe, a drill pipeadvancing and withdrawing means, means for mounting said housing on saidadvancing and withdrawing means with said hollow drive shaft in axialalignment with the drill pipe, a drive gear in said housing, a splineconnection between said drive shaft and said drive gear, a pinion gearin said housing in mesh with said drive gear, means for transferring theaxial load on said drive shaft to said gear in one axial direction only,said means including a thrust bearing for said shaft mounted on saidhousing, a load disc on said hollow shaft abutting said drive gear andmounted on said shaft between said drive gears and said thrust bearing,the shaft being mounted for relatively free movement in said gear in theopposite axial direction, and a thrust bearing in said housing mountedon the opposite side of said gear.

4. A drill head adapted for rotating and advancing and lowering of drillpipe into and from bore holes for wells drilled in the earth, whichcomprises a housing, a hollow drive shaft in said housing, means forrigidly connecting said drive shaft to said drill pipe, a drill pipeadvancing and withdrawing means, means for mounting said housing on saidadvancing and withdrawing means with said hollow drive shaft in axialalignment with the drill pipe, a drive gear in said housing, a splineconnection between said drive shaft and said drive gear, a plurality ofpinion gears peripherally spaced about said drive gear in meshingrelation therewith, a thrust bearing for said shaft mounted on saidhousing, means for transferring the axial load on said drive shaft tosaid gear in one axial direction only, said means including a load discon said hollow shaft abutting said drive gear and mounted on said shaftbetween said drive gear and said thrust bearing, the shaft being mountedfor relatively free Inovement in said gear in the opposite axialdirection, and a thrust bearing in lsaid housing mounted on the oppositeside of said gear.

5. In a power transmission device, a drive shaft, means for connectingsaid drive shaft to drill pipe, a drive gear, a spline connectionbetween said shaft and said drive gear, said shaft being driven by saidgear through said spline connection, pinion gear in meshing engagementwith said drive gear, a power shaft for said pinion gear, a thrustbearing for said drive shaft, means for transferring the axial load onsaid drive shaft only in one axial direction to said gear, said meansincluding a load disc on said drive shaft abutting the side of saiddrive gear between said gear and said thrust bearing, the shaft beingmounted for relatively free movement in said gear in the opposite axialdirection, and a thrust bearing for said gear mounted against theopposite side of said drive gear.

JAMES MOON.

REFERENCES CTED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

